Description: Captopril, an ACE inhibitor, reduces angiotensin II (ATII) levels leading to fall in BP and reduced Na and water retention. Hydrochlorothiazide, a diuretic, contributes to reduction of BP by its natriuretic and diuretic actions and reducing the vol factor.

The ACE inhibitor, captopril, lowers blood pressure and helps prevent strokes, heart attacks, and kidney problems.

Hydrochlorothiazide is a “water pill” (diuretic) that increases the amount of urine you make, causing your body to get rid of extra salt and water. This medication may also be used to treat congestive heart failure.

How to use captopril-hydrochlorothiazide

Take this medication by mouth on an empty stomach one hour before a meal, usually once daily or as directed by your doctor. It is best to avoid taking this medication within 4 hours of your bedtime to avoid having to get up to urinate. Consult your doctor or pharmacist if you have questions about your dosing schedule.

Drink plenty of fluids to prevent losing too much body water (dehydration). If you are on restricted fluid intake, consult your doctor for further instructions.

If you are also taking cholestyramine or colestipol, take captopril/hydrochlorothiazide at least 4 hours before or at least 4 to 6 hours after either of those drugs.

The dosage is based on your medical condition and response to therapy. The manufacturer recommends that daily doses should not be more than 150 milligrams of captopril and 50 milligrams of hydrochlorothiazide.

Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time each day. Do not skip doses or stop taking this medication unless directed by your doctor. It is important to continue taking this medication even if you feel well. Most people with high blood pressure do not feel sick. It may take up to 6-8 weeks before the full benefit of this drug takes effect.

Inform your doctor if your condition worsens (e.g., your routine blood pressure readings increase).

This drug can cause serious (possibly fatal) harm to an unborn baby if used during pregnancy.

Notify your doctor or pharmacist promptly if any of these effects persist or worsen:

  • dizziness
  • lightheadedness
  • drowsiness
  • headache
  • tiredness
  • blurred vision
  • loss of taste
  • dry cough
  • decreased sexual ability
  • increased sensitivity to the sun

This product may cause a loss of too much body water (dehydration) and salt/minerals.

Tell your doctor immediately if any of these unlikely but serious side effects occur:

  • signs of infection (e.g., fever, chills, persistent sore throat)
  • easy bruising/bleeding
  • symptoms of a high potassium blood level (such as muscle weakness, slow/irregular heartbeat)
  • numbness/tingling/swelling of the hands/feet
  • muscle/joint aches
  • decrease in vision
  • eye pain

This drug may rarely cause serious (possibly fatal) liver problems.

Seek immediate medical attention if unusual change in the amount of urine (not including the normal increase in urine when you first start this drug).

A very serious allergic reaction to this drug is unlikely.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.


  • Allergic reaction to this medication.
  • Medical conditions with inability to make urine.
  • Patients with medical history of:
    • kidney problems
    • liver disease
    • gout
    • untreated salt/mineral imbalance (e.g., imbalance of sodium, potassium, magnesium, calcium)
    • loss of too much body water (dehydration)
    • collagen vascular disease (e.g., lupus, scleroderma)
    • recent nerve surgery (e.g., sympathectomy)
    • allergic reaction that included swelling of the face/lips/tongue/throat (angioedema)
  • Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely.
  • Drink enough fluids and avoid heavy exercise, and keep cool in hot weather.
  • Use of potassium supplements or salt substitutes that contain potassium.
  • Before having surgery, tell your doctor or dentist that you are taking this medication.
  • Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.
  • May affect your blood sugar levels.
  • Older adults may be more sensitive to dizziness and unusual change in the amount of urine (kidney problems).
  • Newborn babies may be at greater risk for low blood pressure, a severe decrease in the amount of urine, and seizures.
  • Not recommended for use during pregnancy.
  • Consult your doctor before breast-feeding.

Consult your doctor regarding the precautions mentioned above.



Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions.

Some products that may interact with this drug include:

  • Aliskiren
  • Cisapride
  • drugs affecting the bone marrow (e.g., azathioprine)
  • diazoxide
  • dofetilide
  • certain drugs that weaken the immune system/increase the risk of infection (such as everolimus, sirolimus)
  • lithium
  • probenecid
  • drugs that may increase the level of potassium in the blood (such as ARBs including losartan/valsartan, birth control pills containing drospirenone)
  • other “water pills” (diuretics such as amiloride, furosemide, triamterene)
  • gold injections

A very serious reaction may occur if you are getting injections for bee/wasp sting allergy (desensitization) and are also taking captopril with hydrochlorothiazide.

Some products have ingredients that could raise your blood pressure or worsen your heart failure.

This product can affect the results of certain lab tests. Make sure laboratory personnel and all your doctors know you use this drug.


If overdose is suspected, contact a poison control center or emergency room immediately.

Notes: Do not share this medication with others.

Lifestyle changes such as stress reduction programs, exercise, and dietary changes may increase the effectiveness of this medicine. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.

Laboratory and/or medical tests (e.g., sodium and potassium blood levels, kidney function) should be performed from time to time to monitor your progress or check for side effects. Consult your doctor for more details.

Check your blood pressure regularly while taking this medication, especially when you first start this drug or when your dose is changed. Learn how to monitor your own blood pressure at home, and share the results with your doctor.

Missed Dose: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Storage: Store at room temperature below 86 degrees F (30 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

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